Fertilizer flotation soap



ing any commercial possibilities.

United States Patent C William A. Hodges, Plant City, and Joseph E. Floyd,

Fort Meade, Fia., assignors to Swift & Company, Chicago, 111., a corporation of Illinois No Drawing. Application September 9, 1955, Serial No. 533,523

Claims. (Cl. 209-167) The present invention, which is a continuation-in-part of our earlier application, Serial No. 294,723, filed June 20, 1952, and now abandoned, relates in general to the recovery of oxides of alkaline earth metals from their ores and, more particularly, to an improved reagent and method of using the same in such recovery.

The use of recovery methods such as froth flotation or agglomeration in recovering phosphate values or the like is highly developed, and many reagents have heretofore been proposed which possess a selectivity for phosphate values or the like. Among the most widely used of these reagents has been tall oil. Tall oil is the refined product obtained by acid treatment of the black liquor soap skimmings, produced as a by-product of the sulfate process for the manufacture of cellulose and paper. In this process, Wood chips are digested with various alkalies including caustic soda and other chemicals under pressure. About one-half of the wood is dissolved to produce a black liquor containing excess chemicals and also fats and resins in the form of sodium soap. When this black liquor is evaporated, a scum, known as tall oil soap or black liquor soap skimmings, separates and floats on the surface of the black liquor. This black liquor soap skimmings is removed and then treated with a mineral acid, usually sulfuric acid, and refined to remove ligneous and other insoluble material to produce so-called tall oil. This treatment has been considered necessary in order to produce a product hav- Typical of the general knowledge and belief in the art is the statement appearing in U. S. Patent No. 2,165,268, wherein it is stated: black liquor soap contains ligneous matter and other impurities which render it unsatisfactory as a flotation reagent.

It is therefore an object of the present invention to provide a method for treating black liquor soap skimmings to produce a product which may be used directly as a mineral-recovery reagent.

values.

Additional objects, if not specifically set forth herein,

will be readily apparent to one skilled in the art from the following detailed description of the invention: 7 It has now been found that black liquor soap skimmings ma be so treated as to produce an improved and highly effective mineral-recovery reagent without the necessity for the acid-refining heretofore used by the art. More particularly, it has been found that when black liquor soap skimmings are treated as hereinafter described, and the conditions of pH and specific gravity prescribed carefully maintained, a new reagent is produced which is effective in the recovery of mineral values such as phosphate or the like by either flotation processes.

More specifically, black liquor soap skimmings may be described-as a dark, viscous paste produced as a by-prodnet of the soda and sulfate paper pulp industry. These soap skimmings contain about 45-55% fatty and rosin processes or agglomeration rice acids in the form of soap. They also contain a substantial percentage of free alkaline values as well as a considerable amount of black liquor. It has now been found that by treating black liquor soap skimmings so as to regulate the pH thereof to within the range of from 9.5 to 12.5 and preferably from 11.0 to 11.3, and to adjust the specific gravity to about 1.02-1.03, a reagent is produced which may be used with good success in the recovery of phosphate values or the like. Black liquor soap skimmings are mixed in about a l-to-l ratio with water, and suflicient NaOH is added thereto to bring the pH within the desired range. The resulting liquid soap solution has a solids content of about 35% or more and may be used directly in phosphate-recovery methods.

It has been determined that this reagent is satisfactory both in conventional froth-flotation processes and also in agglomeration by the use of a shaking table, under-water agglomeration screens, and/ or spiral classifiers. The reagent consumption, based on the initial black liquor soap skimmings itself, will be about 1.8 times that of the refined tall oil. However, this increase in reagent consumption is off-set by the considerably lower cost of the reagent and an overall reduction of caustic consumption in the plants.

The following examples are furnished for the purpose of illustration only, and are not to be construed as placing any limitations on the scope of the present invention:

EXAMPLE I A deslimed phosphatic feed was subjected to a conventional flotation operation wherein the feed was first treated with negative ion, phosphate-selective reagents to produce a rougher concentrate, the rougher concentrate then redispersed and refrothed in a secondary flotation cell, and the discharge from this secondary cell subjected to a silica float with positive ion reagents. In this test, two runs were conducted utilizing a conventional tall oil-fuel oilcaustic soda mixture as phosphate flotation reagents. Two additional runs were conducted utilizing the improved reagent of the present invention, i. e. black liquor soap skimmings adjusted to a pH within the range 11.0- 11.3 and having a specific gravity of 1.02, substituted for the conventional refined tall oil. Runs 1 and 2 in the table below illustrate the conventional process utilizing refined tall oil. Runs 3 and 4 illustrate the present method using the improved reagent of the instant invention (identified in table as B. L. reagent):

Reagents (pounds per ton of feed) Run 1 Run 2 Run 3 Run 4 NaOH 0.35 0.35 NaOH 0.25 U. 25 Tall Oil 0. 52 0.75 B. L. Reagent. 0. 1. 88 Fuel Oil. 1. 57 1. 57 Fuel Oil 1. 57 1. 57 H28 04*. 3. 00 3. 00 O 3.00 3. 00 NaOH* 0. l0 0. l0 0.10 0. 10 Ami ue*- 0. 16 0.16 0.16 0. l6 Frother* 0. 16 0.16 Frother 0.16 0. 16

*These reagents are used in the silica flotation. Metallurgical results Run 1 Run 2 Run 3 Run 4 Percentage Cone 36. 2 40.1 41. 3 42.1 Percentage Silica Float Tailings- 3. 1 6. 0 7. 5 12. 1 Percentage Primary Float Tailing 60. 7 53. 9 51. 2 45. 8 B. P. L. Concentrates 78. 5 78.0 77. 81 77.30 B. P. L. Silica Float Tailings 21. 84 14. 36 8. 93 7. 34 B. P. L. Primary Float Tailings. 7.10 4. 0 3. 65 2. 51 SiOz Concentrates 1.84 2. 46 2. 70 3. 27 Percentage B. P. L. Recovery 85.00 91. 30 92. 5O 94. 10

EXAMPLE II A froth-flotation of phosphatic feed was conducted in a manner similar to that described in Example I with the following results-run 5 representing a conventional use of refined tall oil, the runs 6 and 7 illustrating the use of the improved reagent of the present invention (identified in table as B. L. reagent):

while runs '3 and 4 illustrate the use of theimproved reagent (B. L. reagent) of the present invention in the agglomeration process:

utilizing the conventional refined tall oil as a reagent,

Reagents (pounds per ton b feed) 31111 Run 5 311117 Reagents (pounds per ton of feed) 10 Runl R11n2 Run3 B11114 1.28 1.24 2. 3 2. 3 3.00 3. 00 I 0.10 0.10 0.16-' 0.16

0.16 '0. 16 Fuel 011 'Re entsus i sfli h tat on Metallurgical results 7 a P. .R 7 Run UD 6 1m 20 Metallurgzcal results.

Percentage Concentrate 45.37 45.50 44.91 V U Percentage Silica Float Tailings 7.36 0:35 7.12 B11111 B11112 B11113 B11114 Percentage Primary Float Tailings. 47.37 45.15 47.97 j r B. P.'L. Concentrates 71.75 71.80 71.89 V g i j J B. P. L.,Silica Float Tailings 15. 99 14. 50 15. 46 U Percentage Agglomeration COIKL 41. 6 50.2 42. 0 49. B P. L. Primary Float Tailmgs. 3.80 4.11 5. 24 29 Percentage Flotation Cone... 20.5 p I 19. 5 27.1 20. S101 Concentrates.-. 2.78 2.72 2. 61 Percentage Tailings .31. 9 30.3 30.3 .30. Percentage B. P. L.jRecovery 91. 60 91. 50 90. 00 B. P. L. Agglornerati0n-Oonc 74. 93 74. 72 74. 72 74. B. P. L. Flotation Oone 74.00 73.08 73. 76 73. EX PLE In ls3.0P.AL. grailin nu 2.29 4.1 .14 2. g 4. AM i gg omeration one" 6 2 4. 7 1 SiOZ Flotation Conc.* 5.13 6. 27 6.52 6. A froth flotat1on was carried out 1n a plant test using 30 gg g P. Rec Aggloru- 5q 70 S 2 4 a continuous flotation process, similar to that described in p mg' 'ii'ii'ijfiiiiiiiinj 37:1 27:0 37:2 2912 the laboratory results of Examples I and II, and conducted t l P r entage B. I. L. Rec 96.1 97.8 97. 4 97 e in the manner known to the art.- Runs 1 and 2 below 7 7 ill h conventional use f fi d t u i] hil Flotation concentrate was subjected to a silica flotation at further a concentration. runs 3 and 4 illustrate the use of the black liquor soap 5 skimmings reagent (B. L. reagent) of the present invention:

Reagents (grams per minute) 1 EXAMPLE V B 1111 Runz Run3 Run 4 40 V NEOH (100%) V 238 218 116 108 A further test of the agglomerating properties of phos g 540 620 V -5 phatic values was conducted using a Wilfly shaking table. Fuel 011;; .I 2, 390' "2,470 2, 490 2.480 In this test runs 1 and 2 show the results obtained when Metallurgical results Rim 1 Run 2 Run 3 Run 4 BPL S10: BPL S101 BPL SiO: BPL S10:

Feed 39.65 Roughcr Conc 72.08 12. 39 Rougher Tails. 8. Finished 0011c. 78.33 Silica Tails- 25.19 Percent B. Rec. (Rougher Gone.) 88.27 Total Percent B. P.

L. Recovered 84. 65

EXAMPLE IV using theconventional refined tall oil as a reagent. Runs The improved reagent of the present invention was also g f gi i i g the s hquor soap tested in typical agglomeration processes on phosphatic 65 mg eag O P mven ore. T he, deslimed phosphatic feed was mixed with the reagents set forth in the table below and then fed onto a downwardly-inclined screen positioned below the level R e P P" f f I of Water in. a tank. The screen was of such a size as to permit the impurities to pass while retaining the agglom- B11111 B11112 B11113 Run4 erated particles. A further description of this appa-' V ratus and general method may be found in the patent to 8.5% 3.2; 0.10 0.1. McCoy, No. 2,017,468. Four runs were conducted on '5"""6' this type process, run's number 1 and 2 reported below 0 1-85 L39. L

- a e v trative purposes only, and any modifications desired in the procedure may be followed so long as the pH of the Metallurgical results Emu B11112 B g B11114 resulting reagent is within the range 9.5 to 12.5 and preferably within the range 11.0-11.3 and the specific Percentage Concentrate 6 7() 5 6&1 9 5 gravity of the resulting mixture is about 1.02: $i

1,000 gallons of black liquor soap skimmings were iii i i illiiei iir a ij ZIII iliis iiih 32137 $5168 mixed With 1,000 gallons of Water- The Water and p f l 60-97 35-02 55-46 38-39 skimmings were carefully mixed without violent agita- B. P. L. Tailmgs 6.63 6.32 5. 67 4. 61 s goncenmtm" 4,02 g 07 3,92 tion for a period of 10 minutes. Thls is necessary since siosMidlings 2100 54-32 26-87 523 10 violent agitation in mixing causes considerable air' to be 53533632? %I% entrapped in the liquid, increasing the viscosity of the lings Z- 1i uid, and making it very difiicult to pump. Further, Total PercentageB.P. L. Recovered. 96.2 97.0 96.9 97.8 i p skimmings as received from e Sulfate p pe pulp mill, contain a considerable amount of black-liquor EXAMPLE VI which has a high caustic value. This black liquor must be mixed uniformly with the remainder of the product in order to obtain a reagent which will function satis- It is noted that each of the foregoing examples deals with tests conducted using the black liquor soap skimming reagent at the preferred pH, 11.0-11.3. In the tests factorily in the mineral-recovery processes. The liquid detailed below, the effect of the new reagent at a variety Soap thus formed was then adjusted to a pH of 11.1 of pH levels all the way from 9.5 to 12.5 wa investiand a specific gravity of 1.02. The reagent mixture was gated. then used in the plant flotation of phosphate ore.

The deslimed phosphatic feed was subjected to fiota- The pH of the reagent is extremely critical. Unless tion in the conventional fashion with a negative ion, e PH is maintained Within the range 95-125, it has phosphate selective reagent to produce a rougher conbeen found very difficult to produce satisfactory results centrate. This rougher concentrate was redispersed and n mineral-recovery PTOCeSSCS- Should the P of the refrothed in a secondary flotation cell and the discharge reagent p belOW The resulting p oduct assum s a from this cell subjected to a silica float with positive ion roWn color and a sticky, paste-like consistency nd can reagents. First, this procedure was followed using a con- 3 be .Ilsed after a further dilution At high degrees ventional tall oil-fuel oil-caustic soda mixture. Then an of dilution, such a tremendous amount f reagent i additio'nalseven runs were conducted using the reagent 39 quired as to make its use impractical Within the of this invention at pHs of 9.5, 10.0, 10.5, 11.0, 11.5, sPecified P range, the miXtllre is dark Color d, not too 12 d 125 Th hi h H levels were obtained by use viscous and homogeneo us. Here the solids content of f N OH' and low levels (below 115 by the use f no the reagent is in the neighborhood of which more h about 1% l il b d upon the Weight f permits satisfactory results to be attained through the the soap skimmings-water mixture. Sulfuric acid could 35 use of reasonable quantities 0f the Teagentin the also have been used to adjust the pH of the test reagents most pr?ferred range of 19 the miXtUfe is homogeneous to low levels. The pH readings were secured from a and at Its maXlnlum fiuldity- AS the P increases Beckman type electrode, h type recommended for yond 12.0, the mixture again becomes more viscous and making determinations in high alkaline ranges. above 12.5 soap begins to grain out. The product is 40 very difficult to handle.

The term black liquor soap skimmings as used in the specification and appended claims covers the dark, viscous scum obtained, in the manner known to the art and described above, from the black liquor formed in 0-15 the sulfate process of manufacturing paper and cellulose Reagents (pounds per ton of feed) Run 1 Runs 2 Through 8 (L925 from Wood. The term does not cover the product known 3.38 as tall oil which is produced by acid treatment and other refining of the black liquor soap skimmings. The reagent formed from the black liquor soap skimmings has been referred to in the specification as B. L. reagent.

These reagents are used in the silica flotation circuit. Obviously, many modifications and variatio f the Metallurgical results Test Number 1 2 3 4 5 6 7 8 pH 13. L. Reagent- Tall Oil 9. 10.0 10 5 11.0 11.5 12.0 12. 5 Percent Concentrate 3O 66 29. 53 30.36 31 42 30.38 30.69 31.69 30. 50 Percent $11108 Float T 6 90 6. 52 8. 7 48 8. 17 9. 14 9. 15 10. Percent Primary Float Tall! 62 43 63. 95 60. 99 61 1O 61. 46 60. 17 59 16 58. 75 B. P. L. Feed 26 75 26. 29 26. 38 26 05 26. 33 25. 75 27. 61 27. 23 B. P. L. Concentrates 76. 63 76. 04 76. 69 75. 56 76.19 76. 54 75. 93 76.30 B. P. L. Sil ca Float Tallings 26.18 30. 22 21. 17 14. 94 19. 66 19. 29 26. 61 24. 25 B P. L. Primary Float Tailmgs- 2. 32 2. 93 2. 09 1. 94 2. 56 0.83 1 2. 29 S102 Concentrates 2. 02 1. 2. 09 2. 06 2. 03 2. 36 2. 10 1. 92 Total Percent B. P. L. Recoveredu 87. 81 85. 40 88. 25 91. 13 87. 92 91 23 S7. 14 85. 46 Percent P. L. Recovered in Primary Circuit 94. 58 92. 89 95. 19 95. 43 94. 03 98. 06 95. 94 95. 05

*Recovery includes primary and silica float tailings.

invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and there- 70 fore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. An improved reagent for the recovery of oxides of alkaline earth metals from their ores which comprises:

75 black liquor soap skimmings, produced as a by-product of the sulfate process for the manufacture of cellulose and paper, in water solution, said water solution of black liquor soap skimmings having a pHvvithin the range 9.s 12.5. 7 p

a F 2. An improved reagent for the recovery of oxides of alkaline earth metals from their ores which comprises:

9 black liquor soap skimmings, produced as a by-product 4. In a froth-flotation process of separating alkaline earth oxide ore values from the crude ore, the step which comprisesz subjecting the ore to froth-flotation in the presence of a black liquor soap skimmings-water mixture having a ratio of soap skimmings to water of about 1:1, said soap skimmings-water mixture having a pH within the range 9.512.5.

5. The process of claim 4 wherein the ore treated is phosphatic ore.

6. In a froth-flotation process of separating alkaline earth oxide ore values from the crude ore, the step which comprises: subjecting the ore to froth-flotation in the presence of a black liquor soap skimmings-water mixture having a ratio of soap skimmings to water of about 1:1, said soap skimmings-water mixture having a pH within the range 11.0-11.3. 6

7. In the recovery of alkaline earth ore values from the crude ore by agglomeration, the step which comprises: subjecting said ore totthe action of a 'black liquor soap skimmings-water mixture having a ratio of soap skimmings to water of about 1:1, said. .soap skimmingswater mixture having a pH within the range 95-125.

8. The process of claim 7 wherein the ore treated is phosphatic ore.

9. In the recovery of alkaline earth ore values from the crude ore by agglomeration, the step which comprises: subjecting said ore to the action of a black liquor soap skimmings-water mixture having a ratio of soap skimmings to water of about 1:1, said soap skimmings water mixture having a pH within the range 11.0-11.3 10. In the recovery of alkaline earth ore values from the crude ore by agglomeration, the step which comprises: subjecting said oreto the action of a black liquor soap skimmings-water mixture having a specific gravity of about 1.02, said soap skimmings-water mixture having a pH within the range 11.0-11.3.

. References Cited in the file of this patent UNITED STATES PATENTS 2,249,569 Phelps July 15, 1941' 2,466,671 Gieseke V Apr. 12, 1949 FOREIGN PATENTS V 532,866 Great Britain Feb. 15, 1941 t 

3.AN IMPROVED REAGENT FOR LTHE RECOVERY OF OXIDES OF ALKALINE EARTH METALS FROM THEIR ORES WHICH COMPRISES: BLACK LIQUOR SOAP SKIMMINGS, PRODUCED AS A BY-PRODUCT OF THE SULFATE PROCESS FOR THE MANUFACTURE OF CELLULOSE AND PAPER, IN WATER SOLUTION, SAID WATER SOLUTION OF BLACK LIQUOR SOAP SKIMMINGS HAVING A PH WITHIN THE RANGE 11.0-11.3 AND A SPECIFIC GRAVITY OF 1.02-1.03. 